Automatic liquid-level control



Jan. 28, 1930. J. c. CARAWAY ET AL 1,744,723

AUTOMATIC LIQUID LEVEL CONTROL By M 77% Filed Sept 17, 1927 INVENTORJ James 6. Caraway and flare/d JF y w QQ Q QQ A TTORNEYJ Patented Jan. 28, 1930 UNITED STATES PATENT ol-"Flca JAMES C. OARAWAY, OlE COMPTON, AND HAROLD J. REYNOLDS, OF HERMOSA. BEACH,

CALIFORNIA I AUTOMATIC LIQUID-LEVEL CONTROL Application filed September 17, 1927? Serial No. 220,234.

This invention relates to a device for controlling the level of liquid in a receptacle.-

It is especially suitable for use with steam generators such as are supplied with feed water by a pump, but in no way limited as a part of such a combination. For convenience of illustration of the invention, it will be described as a part to a steam boiler supplied with water by a feed water pump. Devices operable by floats disposed within a boiler have been used to control and regulate the feed water supply. Such devices encounter certain practical difliculties such as collapse of the float, which makes them objectionable. Thermodynamically operated devices have also been employed. These .are delicate and easily become inoperative.

The present invention relates to a device of the character described which is mechanically operated by variation of liquid level in the receptacle, employs no float, is simple in structure, positive in operation economical to build, does not get out of order easily, is. compact, strong and durable. Broadly it is an object of this present invention to provide a device controlling the source of water sup ply and operable by the balance chamber which contains a volume of water commensurate with the water level in the boiler.

These objects together with other objects and corresponding accomplishments are ob-. tained by means of the embodiment of our in vention illustrated in the accompanying drawing, in which the figure is a diagrammatic showing of the connections of the parts,

part of the section.

A fragment of the wallof a steam gener ator or boiler is indicated by 1. dash line 2 indicates the water level. A feed waterspump is indipated is of the steam type having a steam end 4 and a water end'5. The water intake line for the pump is indicated by 6 and the feed line by 7. In the present instance, a'valve 8 of any suitable type is disposed in the feed water line and is actuated by means of an arm9. .Mounted upon a stationary support, such as the wall of the steam generator is a bracket balance chamber being shown in The dot andgenerally by 3. It

10 having a lever 11 pivotally secured there shelf 13 extends from be adjusted as to its position and fixed in place by a set screw 16.

The other end. of the leveris forked and secured by shackles 17 to a balance chamber 18. This balance chamber is closedhavinga tubular extension 19 at one. end and a like extension 20 at the other. These-tubular members are in alignment and extending theret hrough is a water level tube 21. At the chamber, the tube 21 is provided with ports 22 and 23 for communication of the bore of the tube with the chamber. tubular members 19 and 20 the tube is enlarged as indicated by 24 and provided with an annular recess in which is packing 25 preferably snap rings. The arrangementis such that the-.chamber 18-may-slide a limited dis-' usual manner. A gauge glass 29 is shownoli the water column. Pivotally secured to the lever 11 intermediate the shackles 17 and the fulcruml2 is a connecting rod 30. This conyss At the necting rod is secured at its lower end to'the arm 9 of the valve 8.

The structure just described operates in the following manner: The level of water in the steam generator, in the water column and in the balance chamber 18 will be the same as they are in free communication. Any change in the level of the water within the steam generator will befollowed by a corresponding change in the balance chamber. Suppose that the level of liquid lowers below the normal. The we'rght of liquid Within the balance chamber is decreased and the balance weight 15, causes the balance chamher to be moved upwardly upon the tube 21.

This causes the connecting rod 30 to be raised,

rais-' and water is fed by the pump to the boiler. The level of the water in the boiler rises and likewise in the balance chamber. This increases the volume of water in the balance chamber and eventually the balance chamber overbalances the weight 15 and moves downwardly. This causes the connecting rod to move arm 9 down and close the valve. The stop posts 14 prevent the lever 12 from moving too far.

We have shown herein the tube 21 connected to a water column. However, the tube will function just as well if connected directly to the shell of the boiler. We have also shown the chamber controlling the water line. It is obvious that the steam end of the pump may as well be controlled. There are also certain refinements, such as providing a by-pa'ss for water to flow from the discharge to the intake side of the pump when the valve 8 is closed, in order to prevent stalling of the pump. However, these are all features of construction well within the skill of those familiar with the art; It is obvious that the device may be applied to other than steam generators, and to other liquids than water. In steam boilers there is a consant rapid pulsation or vibration during operation. This will cause the chamber to vibrate up and down on tube 21. The result is that the rings \25 will not stick and the chamber is maintainedin condition to be freely moved up and down with change in water level.

What we claim is 1. A liquid level control comprising the combination -of a receptacle in which the atively connected to said lever to control the flow of liquid from said source of supply.

In witness that we claim the foregoing we have hereunto subscribed our names this 9th day of September, 1927.

J AMES 0. CARAWAY. HAROLD J. REYNOLDS.

liquid is to be controlled, a closedbalance chamber, a pipe connected to said receptacle to form a water level tube, said chamber being slidably disposed on said water level tube to be moved longitudinall thereon and in communication with the" ore thereof, the parts of said chamber being arranged so that said chamber may be moved gravitatively, a counter-balance for said chamber, a source of liquid supply for said receptacle, and

means operatedby movement of said chamber to control the flow 9f liquid from said source of supply.

2. A liquid level combination of a receptacle in which the liquid is to be controlled, a closed balance chamber having alined openings at the top and bottom, a pipe connected to said receptacle and having an upright portion forming a water level tube, said upright portion extending through said openings and sealed therein toslidably mount said chamber thereon, ports in said pipe communicating with said chamber, a support for said chamber comprising a lever from one end of which the chamber depends, a counter-balance at the other end of said lever, a source of liquid control comprising the: 

